Level up your cookie game, these 10 baking tips will make a huge difference 1. Bake a tester cookie first. Don’t risk the whole batch! Bake one cookie and adjust as needed. If the cookie spreads too much, mix in ¼ cup of flour. If it doesn’t spread enough, add 1 tablespoon of milk. You can bake another tester until they’re just right. 2. Heat-treat your flour for edible cookie dough. Raw flour isn’t safe to eat as-is. To heat-treat it, spread a thin layer on a baking sheet and bake at 300°F for